It’s About to Rain Flies in Texas, but Only to Stop the Flesh-Eating Maggots

The U.S. government is reviving an old Cold War-style tactic to combat a tiny but terrifying threat: the New World screwworm fly, a small tropical insect whose larvae burrow into the flesh of living animals and eat them from the inside out.

If left unchecked, these maggots can take down cattle, wildlife, pets, and even humans, as I recently covered in the story about how New World screwworms are terrorizing Honduras. If they run amok, our food supply would be in a state of full-on crisis in a matter of weeks.

To stop the larval menace, the Department of Agriculture is preparing to breed and drop hundreds of millions of sterile male flies over southern Texas and Mexico. The flies will be zapped with radiation, stripped of their reproductive powers, and then tossed out of airplanes. Female screwworms, who only mate once in their short adult lives, will pair up with these duds and lay eggs that never hatch. Over time, the population collapses.

The tactic isn’t new. Back in the 1960s and 70s, the US and Mexico deployed over 94 billion sterile flies to eradicate the pest north of Panama. The program was so effective that, in typical American fashion, we assumed we had completely solved the problem, so we shut down fly factories in Florida and Texas, before patting ourselves on the back and walking off into the sunset not realizing that the New World screwworm’s arm burst out of a heap of rubble just before a cut to credits.

But then, in late 2024, screwworms were spotted in southern Mexico and throughout Central America, prompting the USDA to resume its eradication program. Plans are currently underway to build a new $21 million fly-breeding facility in Mexico and a $8.5 million distribution center in Texas by 2026. There’s already a facility in Panama churning out 117 million sterile flies per week, soon to be quadrupled. These flies are raised on a scrumptious diet of blood plasma and egg powder, then carefully packed and air-dropped across areas at risk.

All that stands between us and an army of insects hell-bent on eating our food supply, and us, from the inside out, is a legion of flies that are shooting blanks.

It sounds absurd, completely ridiculous, totally gross, but, as an assistant professor from the University of Florida who studies parasites, Edwin Burgess, told CBS News, the sterile fly breeding program is one of the USDA’s “crowning achievements.” Considering there is meat to eat and we are not currently being eaten alive by screwworm larvae, I’m inclined to agree.